rapidio: devices: fix missing put_device in mport_cdev_open

[ Upstream commit d5b6e6eba3 ]

When kfifo_alloc fails, the refcount of chdev->dev is left incremental.
We should use put_device(&chdev->dev) to decrease the ref count of
chdev->dev to avoid refcount leak.

Link: https://lkml.kernel.org/r/20221203085721.13146-1-caixinchen1@huawei.com
Fixes: e8de370188 ("rapidio: add mport char device driver")
Signed-off-by: Cai Xinchen <caixinchen1@huawei.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Jakob Koschel <jakobkoschel@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/rapidio/devices/rio_mport_cdev.c

@@ -1911,6 +1911,7 @@ static int mport_cdev_open(struct inode *inode, struct file *filp)
 			  sizeof(struct rio_event) * MPORT_EVENT_DEPTH,
 			  GFP_KERNEL);
 	if (ret < 0) {
+		put_device(&chdev->dev);
 		dev_err(&chdev->dev, DRV_NAME ": kfifo_alloc failed\n");
 		ret = -ENOMEM;
 		goto err_fifo;